Well drilling apparatus



Nov; 24,` 1942.'

R. R. scHwErTzER' WELL DRILLING APPARATUS Filed Feb. 24, 1941 Patented Nov; 2.4, 1942 WEIL DRILLING APPARATUS Reuben Richard Schweitzer, Norfolk, va., ossirn or. to Layne & Bowler, Incorporated, Memphis, Tenn., a corporation of Delaware Appiiootiorr February 24, 1941. serial No. 380,089

(ci. c55-"asi 5 Claims.

This invention relates to certain new and useful improvements in` well drilling apparatus, and particularly to an improved construction of guide barrels for drill bits.

It is desirable for the well hole to be drille with accuracy and with as little deviation as possible. Owing tovariations in strata, ordinary drill bits, following the path of least resistance, cut unevenly and often cause the well hole to seriously deviate, and such deviation often seriously impedes or prevents handling of the casing.

In such drilling removal of the tools is often diflicult and even impossible of accomplishment requiring abandonment of the well, because of the tendency of the cuttings to settle above the drilling apparatus, and also because of the tendencies of the mud fluid, often necessarily used to choke off porous formation or to assist in discharge of cuttings, to form a .lter cake" on the well wall, creating what is often termed by drillers a squeeze which freezes the tools against removal.

The principal object of this invention is to provide a well bit which will minimize deviation from the vertical in drilling a well. v

A further object is to provide such a bit with an elongated guide barrel or cylinder having very small'clearance from the wall of the well, and having means carried by the barrel for preventing closure of such clearance.

A further object is to provide means for weighting such a barrel to assist drilling.

A further object is to provide well drilling apparatus having the drill rod or pipe weighted Fig, 1 is a side elevationof my well drill in use-position in a partially out well hole; arid.

Fig. 2 is a similar fragmentary view, onan enlarged scale, with portions broken away showing details of the construction. e

Referring now to the drawing in which the various parts are indicated by numerals:-

II is a rotatable drill pipe or Vstem around the lower portion of which is secured a hollowy guide barrel or shell I3, which is of considerable length relative to the diameter of the well hole, as say twenty feet for a drill hole of eight.t een inch diameter. 'I'he diameter of the guide barrel is preferably such that only a very slight annular clearance I2 is provided between it and the wall I5 of the drill hole. Thus for a drill hole of a -diameter of eighteen inches the diameter of the guide barrel would preferably be seventeen and one-half inchs, minimizing the possibility of variation-in the line of drilling. Guide barrel I3 is concentric with drillpipe II and is carried by an upper annular disc I1 and a lower annular discL I9, which vare respectively secured, preferably by welds I4, I6, I8, and 20, to both drill pipe II andthe inside ofA barrel I3. Upper disc I1 isprovidedl with a filling hole or holes 2I adapted for receiving weighting material, as concrete 22, Any other suitable weighting material however, as sand, or barite may be introduced into barrel I3 as desired. Disc I9 is secured tothe barrel and the drill pipe adjacent the lower end of the barrel, and extendingl below disc I9 is a barrel skirt 23, which is serrated tovprovide teeth 25, which are preferably and usually faced with hardened cutting material to form grinding or cutting edges.

Drill pipe II extends longitudinally through barrel* I3 and protrudes below teeth 25. Dependi ed from the lower end of drill pipe II is a drill;L bit 2l, which is removably secured to the drill, pipe, the inner surface of the lower end of the drill pipe preferably being threaded as at 3| to receive the shank of thebit, which is provided with complementary threads. Drill pipe II is preferably hollow and is used to carry water forced downward for flushing chips, cuttings, and other detritus from the drill hole as work' progresses. 'Drill bit 21,is provided with a central passage 33, and discharge ports 29, the flushing water discharging downward through passage 33V and ports 29, additional velocity being imparted by the relative restriction of size of the ports.

Carried by and secured to the upper portion of barrel I3, are a plurality of reamer blades 35, which are preferably beveled as at 3l, and are preferably rigidly secured along the bevel to the barrel. The bevels'31 are preferably long bevels,

and provide a gradual outward flaring of reamer blades 35 as they extend upwardly,`the maximum flare being achieved substantially at the top of barrel I3. Reamer blades 35 maybe bentv inwardly as at 39 to form spacer portions 40, the

inner ends of which are rigidly secured to barrel I3 as at 3|. It will be understood that While this inward bending of the reamer blades is preferred practice, providing the most eillcient manner of forming the reamer blades, they may be spaced and secured otherwise as for instance byl interposing independent members which may be secured as at 39 and 3l. Reamer blades 35 are preferably provided with cutting edges 33, of usual and well known commercially available material, and are adapted to enlarge the drill hole, o

and by their tapering contact with the walls of the drill hole assist materially in preventing wobf bling of barrel I3 or deviation of bit 21. V45 are braces which preferably form upward and inward.

continuations of the reamer blades andmay be similarly provided with cutting edges, and are of primary importance in cutting through and loosening up accumulations of cuttings, filter cake or other obstructions which resist removal of the apparatus after drilling. They are preferably secured to the ends of the reamer blades and extend upwardly therefrom and inward toward the drill pipe to which they are also secured, as by welding.

In construction of my improved drilling apf- `paratus, disc I9 is secured to drill pipe II, pref some' of the well known commercial types.

Reamer blades 35 are preferably formed of integral rectangular bars, the edges of which are similarly faced in usual manner to provide hard ened cutting edges I3. The upper ends of the bars are bent inward at 39 to provide shallow upper end spacers and the bars extend downward from such spacers along the exterior of barrel I3. 'I'he lower ends of the bars are preferably beveled to form the long tapers 31, this beveling usually being accomplished by burning the bars down on an angle, although it may be accomplished otherwise.

The bevels 31 are formed to provide gradual flaring of the reamer blades 35 away from barrel I3, the flare `reaching* its maximum at bend 33, adjacent the top of barrel I3.

In securing blades 35 to barrel I3, the inner end of the spacer 33 of each reamer blade 35 is secured, preferably by welding, as at 3l, to. barrel I3 adjacent its top. The reamer blade is extendeddownwardly therefrom so that bevel 31 contacts and lies along an intermediate portion of the exterior of4 barrel I3. The lower end of -35 carried by the upper end of barrel I3 engage each blade 35 is secured to barrel I3 by securin"V the bevel portion 31 to the barrel as by welding along the length of bevel, although spot welding, as at the top and bottom 0f the bevel, is satisfactory, as well as-numerous other methods.

After blades 35 are secured to barrel I3 as de scribed, and barrel I3 has been secured to drill pipe II, the additional braces 35 may be used, ad

ditionally securing barrel I3 to drill pipe I I. The lower ends of braces- 35 are rigidly secured to the upper ends of blades 35, and their upper ends t0 drill pipe I I, preferably by welding.

Bit 21 is screwed into engagement with 15 threaded portion 3| of the drill pipe, and extends well. below the teeth 25. Suitable weighting material, as concrete 22, may be introduced into barrel I3 through opening 2|, in such quantity as may be desired. Several materials, particularly barite, because of its high specific gravity, have been found to be highly satisfactory for weighting and may be substituted for concrete.

When drilling is begun, due to the arrangement which has been herein described, drill bit 21, being depended below barrel I3, may be immediately used to drill even the most shallow of holes. As the extra weight is carried in barrel I3 it is also immediately above the bit, and is available even in a shallow hole. After drilling passes the preliminary stages, thelength and diameter of barrel I3 are such that a deviation from the line of drilling is substantially prevented. In addition, since weighted barrel I3 is placed adjacent bitl 21, the weight is at the bottom of 'the drill pipe II and this is highly desirable for keeping the drill hole straight, as its depth increases, and lengthening of the drill pipe is necessary for operation.

During drilling water is forced downward through drill pipe I I, and discharges downwardly throughI passage 33 and ports 29 of bit '21, for flushing chips, etc., from the drill hole. This flushing water and detritus carried thereby discharges upwardly through the minor annular c1earance l2 between barrel ls and the wan I5 of the drill hole, and subsequently discharges at :the surface.

, The relatively minor amdunt of clearance affords an opportunity for discharging refuse to clog as it discharges upwardly, particularly as it reaches the lower end of the barrel and enters the minor annular clearance I2. It is for this reason that barrel skirt -23 is preferably serrated to form teeth 25. Teeth 25, upon drilling rotation of the apparatus, serve to grind and cut away any mass.

that may accumulate at the point of entrance to the annular clearance space I2, thereby preventing closure of the clearance space, and permitting passage of only those materials whose size is such as to readily be discharged upwardly with the flushing waters. It will be understood that teeth 25 may be formed in other manner than as shown without departing from my invention.

As drilling progresses downward, reamer blades wall I5 and enlarge the drill hole to the desired size, and by their'tapering contact with well wall I5, firmly hold the barrel I3 and blt 21 in position withoutV lateraldisplacement. vReamex blades 35 are spaced apart around barrel I3 and donot impede the upward discharge iiow of the flushing water.

After drilling has been completed, the drill pipe and attached barrel and bit are raised from the well. If minor accumulations only of filter cake and cuttirms exist, the braces and reamer blades pull through and removal is accomplished.

' Ordinarily however it is necessary to rotate the A,drill pipe and through the barrel to rotate the braces and blades and-loosen the cuttings and/or filter cake, to permit such removal; pumping of fluid through the drill pipe usually also being continued toeffect the removal of such loosened materials.

It will be understood that, while barrel I3 has been herein .described as hollow, it may be solid, furnishing thereby the desired additional weight.

The barrel has also been described as beinl secured adjacent its upper end to drill pipe II through apertured disc II. It will be understood that the means for securing the upper portion lof the barrel are notl to be limitedl to an apertured discbut other suitable means may be substitutedltherefor. Thus, for example, radial arms might be employed without departing from my invention. It will alsoI be understood that bit 2l need not vbe depended any appreciable' distance below barrel I3, but may be secured to drill pipe I I at such distance below the barrel'as is desired.

I claim:

y1. In an assembly for drilling a well which includes a rotatable drill pipe and a drill bit depended therebelow, means for guiding said bit during drilling which includes, in combination. a barrel, secured around said drill pipe, having -a diameter less` than the diameter of said bit with an annular clearance between said barrel and the wall of said well; and well-contacting means carried by the upper portion of the length of said barrel, comprising a plurality of arms secured to said barrel intermediate its length, andconnected to the periphery of the .top of said barrel and spaced therefrom, said arms being adapted to wedgingly contact said well wall to prevent sway of the upper portion .of said barrel, and upon rotation to taperingly enlarge said well adjacent the upper portion, of said barrel to facilitate subsequent removal of said assembly from said well.

2. In an assembly for drilling a well which includes a rotatable drill pipe and a drill bit detending upwardlyfrom said'intermcdiate securf ing and outwardlyirom the surface ol' said bar-` rel, and beingl connected to the periphery of the topv of said barrel and spaced therefrom, .said arms being'adapted on assembly rotation to ytapeiingly enlarge said well adjacent the upper portion of said barrel, and a plurality'of stirrers secured to the top ol" said barrel, extending upwardly from said barrel top and inwardlytoward said drill pipe, and being secured to said drill pipe,

pended tlierebelow, means for guiding said bit during drilling which includes, in combination, an elongated cylindrical barrel, secured around said drill pipe, having 'a diameterl slightly less than the diameter of said bit and adapted to closely t said well with a minor annular clearance only r a plurality of arms secured to said barrel intermediate its length, said arms extending upwardly from said intermediate securing, and outwardly from the surface of said barrel, and being connected to the periphery of thev top of said barrel and spaced therefrom,said.arms being adapted to wedgingly contact said well wall to prevent sway of the upper portion of said barrel, and, upon rot-ation, to taperingly enlarge said well adjacent the upper portion of said barrel to facilitate removal of said assembly from said well.

3. An assembly for drilling a-well which includes a rotatable drill pipe, adapted to carry uid downward into said well for flushing detritus therefrom; a drill blt-depended therebelow; an

l elongated guide barrel secured around the lower portion of said drill pipe, said guide barrel having a diameter slightlyb less than the diameter of said bit to closely t said well, with a minor annular clearance only between said barrel and the wall of said well, to permit said uid and detritus to discharge upwardly through said annular clearance; and means for facilitating the removal of said assembly from said well which inand adapted on assembly rotationto agitate said iluid and detritus carried thereby.

-4. An assembly for drilling a well which in- 'cludes a rotatable drill pipe adapted to carry `fluid downward into said well for flushing detritus therefrom; a drill bit depended therebelow; an

elongated cylindrical guide barrel secured around j which includes a pluralitypf teeth' formed in`v the lower vend of said barrel, said teeth being adapted to grind and disintegrate masses of detritus approaching said annular` space, a plurality of arms, carried by the upper portionv of the length of said barrel, secured to said barrel intermediate its length,V said arms extending upwardly from said intermediate securing, .and outwardly from the surface of said barrel, and being connected to the periphery ol' the top of said barrel and spaced therefrom, said arms being adapted on assembly rotation to taperingly enlarge said well adjacent the upper portion ol' saidbarrel, and a plurality of stirrers secured to the top of said barrel, extending upwardly from said barrel topV and inwardly toward said drill pipe, and being secured to said drill pipe,

and adapted on assembly rotation to agitate said uid and detritus carried thereby to minimize deposit thereof on said barrel top.

5. In an assembly for drilling a well, which includes a rotatabledrill pipe and a drill bit, means for guiding said bit during drilling which includes, in combination, a barrel secured around said'drill pipe; and well-contacting means, carlried by the upper portion of the length of said REUBEN RIcHARD scHWErrzER. 

